As a technique relating to this kind of air cell, there is disclosed one called a “water cell” disclosed in Japanese Registered Utility Model No. 3152998, which includes a first and a second end part where two water injection ports are formed, an in-negative-electrode cylindrical body made of metal, powder filling material which is made of oxide material and filled in the in-negative-electrode cylindrical body, and a rod-like positive electrode current collector which is configured with a carbon inserted into this powder filling material, in an inside of the in-negative-electrode cylindrical body, a separation wall is provided for separating the inside, and on the second end part side of the inside, a space part where the powder filling material is not filled is formed. Another related technique is illustrated in Japanese Patent Application Laid-Open Publication (Translation of PCT Application) No. 2005-527069.